8557021440 has 864 divisors, whose sum is σ = 34873517952. Its totient is φ = 1990656000.

The previous prime is 8557021439. The next prime is 8557021463. The reversal of 8557021440 is 441207558.

8557021440 is a `hidden beast` number, since 85 + 570 + 2 + 1 + 4 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 8557021395 and 8557021404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 140279010 + ... + 140279070.

It is an arithmetic number, because the mean of its divisors is an integer number (40362868).

Almost surely, 2^8557021440 is an apocalyptic number.

8557021440 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8557021440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17436758976).

8557021440 is an abundant number, since it is smaller than the sum of its proper divisors (26316496512).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

8557021440 is a wasteful number, since it uses less digits than its factorization.

8557021440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149 (or 123 counting only the distinct ones).

The product of its (nonzero) digits is 44800, while the sum is 36.

The square root of 8557021440 is about 92504.1698519586. The cubic root of 8557021440 is about 2045.3809497884.

Adding to 8557021440 its reverse (441207558), we get a palindrome (8998228998).

The spelling of 8557021440 in words is "eight billion, five hundred fifty-seven million, twenty-one thousand, four hundred forty".